Apparatus and method for slitting fabric on a circular knitting machine

ABSTRACT

The slitting apparatus includes a vertically movable cutter positioned inside of the needles to engage the fabric as it is drawn from the needles and downwardly through the needle cylinder. Control means is provided for, at times, positioning the cutter in the path of movement of the fabric to slit the fabric in a walewise direction and for, at other times, maintaining the cutter below the level of the fabric so that the fabric is not slit thereby.

[451 June 20, 1972 [54] APPARATUS AND METHOD FOR SLITTING FABRIC ON A CIRCULAR KNITTING MACHINE inventor:

Assignee:

Filed:

Appl. No.:

Sept. 4, 1969 U.S. Cl.....

Int. Cl.

Field of Search Oscar Fregeolle, Hickory, N.C.

Pilot Research Corporation, Valdese, N.C.

[56] References Cited UNITED STATES PATENTS 2,933,908 4/1960 Thore ..66/ 147 Primary Examiner-Ronald Feldbaum Attomey-Parrott, Bell, Seltzer, Park 8: Gibson [57] ABSTRACT The slitting apparatus includes a vertically movable cutter positioned inside of the needles to engage the fabric as it is drawn from the needles and downwardly through the needle cylinder. Control means is provided for, at times, positioning the cutter in the path of movement of the fabric to slit the fabric in a walewise direction and for, at other times, maintaining the cutter below the level of the fabric so that the fabric is not slit thereby.

10 Claims, 9 Drawing Figures FATENTEJUHZO I972 SHEET 2 OF 4 INVENTOR: QSCAE. FQEGE-OLLE JE, f1

ATTORNEYS PATENTEDJum m2 SHEET R [If 4 INVENTOR:

OE CAR FEEGEOLLE:

MMJM4M ATTORNEYS APPARATUS AND METHOD FOR SLI'ITING FABRIC ON A CIRCULAR KNITTING MACHINE This invention relates generally to circular knitting machines of the type adapted to produce tubular fabrics and more particularly to an apparatus and method for slitting the tubular fabric in a walewise direction immediately after the fabric is knit.

There are many instances in which it is desirable to slit knit tubular fabrics. For example, in the hosiery industry, it is the general practice to form elongated seamless hosiery blanks and to then form a slit extending in a walewise direction for a definite length from one end. Pairs of these slit blanks are then connected together along the slit edges to form a panty hose type garment. In the apparel trade, it is the practice to knit large diameter tubular fabrics on circular knitting machines and to thereafter slit and spread the fabric so that various garment parts may be cut therefrom.

To prevent waste, the fabric should be slit along a particular wale. However, this requires accurate alignment of the fabric and the cutter so that the accurate positioning of the slit is dependent upon the skill and accuracy of the operator.

With the foregoing in mind, it is an object of the present invention to provide a method and apparatus for accurately slitting tubular fabric in a walewise direction as the fabric is being knit on a circular knitting machine.

It is another object of the present invention to provide a fabric slitting apparatus which may be incorporated in a wide variety of different types of single or multiple feed circular knitting machines and is positioned to operate in such a manner as it does not interfere with the normal operation of the cylinder needles or the dial instrumentalities.

In accordance with these objects, the present slitting apparatus includes a vertically movable cutter blade positioned inside of the needle cylinder and closely adjacent the circle of needles for severing coursewise extending portions of the yarn in successive courses. The present slitting apparatus is particularly adapted for use in forming a single walewise extending slit in the tubular fabric, however, it is to be understood that the present slitting apparatus may also be utilized in forming multiple slits by merely positioning a vertically movable cutter blade at each position inside of the needle circle or cylinder where it is desired to form a walewise slit. By providing a plurality of vertically movable cutter blades on the inside of the needle cylinder, it is possible to slit and separate large tubular fabrics into two or more strips, as they are withdrawn from the knitting machine. Since the present slitting apparatus does not interfere with the normal operation of the needles, the sinkers, or transfer elements, any preferred type of fabric may be knit having any pattern of special stitches formed therein or having separate elastic or stretchable yarns inlaid or interknit with the usual body yarn.

The present slitting apparatus is illustrated and described in connection with a circular hosiery knitting machine having a rotating needle cylinder, however, it is to be understood that the slitting apparatus is not limited to use with this particular type of machine.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds when taken in connection with the accompanying drawings, in which:

FIG. 1 is a fragmentary isometric view of the upper portion of the needle cylinder of the knitting machine and illustrating the manner in which the vertically movable cutter blade is supported inside of the needle cylinder;

FIG. 2 is a view similar to FIG. 1 but illustrating the manner in which the knit fabric is slit in a walewise direction as it is drawn inwardly and downwardly through the needle cylinder and into engagement with the vertically movable cutter blade;

FIG. 3 is a vertical sectional view through the upper portion of the needle cylinder, the dial and the sinker bed, illustrating the manner in which the vertically movable cutter blade is supported in an active position inside of the needle cylinder;

FIG. 4 is a view similar to the right-hand portion of FIG. 3 but illustrating the vertically movable cutter blade in a lowered or inoperative position so that the knit fabric passes above same and is not slit thereby;

FIG. 5 is an exploded isometric view of the needle cylinder and associated parts and illustrating the control means for selectively positioning the slitting apparatus in the operative and inoperative positions;

FIG. 6 is a fragmentary isometric view of a portion of the cutter support ring, the movable and fixed cutting blades being shown in exploded position;

FIG. 7 is an elevational view of the central portion of FIG. 6 with the parts in assembled position;

FIG. 8 is an enlarged horizontal sectional view, being taken substantially along the line 8-8 in FIG. 7; and

FIG. 9 is a vertical sectional view taken substantially along the line 9-9 in FIG. 8.

Generally, the present slitting apparatus includes cutting means, broadly indicated at A, (FIGS. 1 and 5) positioned inside of the knitting machine needle cylinder 10 and closely adjacent a circle of needles N supported in the usual manner in slots in the needle cylinder 10. Cam means, broadly indicated at B, is supported inside of the needle cylinder 10 and is operable to impart vertical movement to the cutter means A in timed relationship to the knitting of the fabric. Control means, broadly indicated at C, (FIG. 5) is operably associated with the cam means B for, at times, positioning the cutting means A in a raised or operative position in the path of movement of the fabric as it is drawn from the needles to slit the fabric in a walewise direction, as illustrated in FIG. 2, and for, at other times, maintaining the cutting means A in a lowered or inoperative position below the level of the fabric so that the fabric is not slit thereby but is drawn downwardly through the needle cylinder without being slit, as illustrated in FIG. 4.

The present slitting apparatus is illustrated in operation with a four feed circular knitting machine of the type manufactured by Textile Machine Works, Reading, Pennsylvania. The conventional parts of this knitting machine will first be described and the present slitting apparatus and method will then be described in connection therewith.

The needle cylinder 10 is supported in the usual manner on the upstanding portion of a sleeve gear 12 (FIG. 5) which may be selectively rotated or reciprocated by the main drive of the machine, not shown. A plurality of tension springs 13 (only one of which is shown in FIG. 3) are connected at their lower ends to the upper portion of the sleeve gear 12 and their upper ends are suitably connected to spring perches I4, fixed on the inner wall of the needle cylinder 10. The springs 13 urge the needle cylinder to a lowermost position on the sleeve gear 12 and return the cylinder to its lowermost position, after it has been lifted by the conventional stitch length adjusting mechanism, not shown.

An inside sinker ring 15 (FIG. 3) is fixed on the inner portion of the upper end of the needle cylinder 10 and its upper peripheral edge is provided with radial grooves to support the inner ends of sinkers S for radial sliding movement therein. The outer portions of the sinkers S are supported for radial sliding movement in the radial grooves of an outer sinker ring or bed 16 which is suitably supported on the outside and upper end of the needle cylinder 10. The sinkers S extend inwardly between the needles N and the sinker rings 15 and 16 rotate with the needle cylinder 10.

A sinker cap 17 is supported in a non-rotating position on the sinker bed 16 and is provided with conventional cams which engage the upstanding butts of the sinkers S to control the radial position thereof. A latch ring 18 is supportedin the usual manner in spaced relationship above the sinker cap 17 and includes the usual yarn feeding throat openings, not shown, at each knitting station for feeding the yarn to the needles N. The usual stitch cams, not shown, are provided at each knitting station for imparting vertical movement to the needles, which are resiliently maintained in the slots by spring bands 20, positioned in a groove surrounding the upper portion of the needle cylinder 10.

A dial bed 22 is drivingly supported on the lower end of a drive shaft 23 (FIG. 3) and is provided with radially extending grooves in which dial transfer points or bits 24 are supported for radial movement. The outer peripheral edge of the dial bed 22 is positioned closely adjacent to and inside of the circle of needles and the transfer bits 24 are aligned with every other cylinder needle N. A dial cap 25 is supported in a non-rotating position and contains the usual transfer bit operating cams, indicated at 26, for controlling the radial position of the transfer bits 24 as they rotate in timed relationship with rotation of the needle cylinder 10 and needles N.

A fabric guiding funnel 30 (FIG. 3) is positioned inside of the upper portion of the needle cylinder 10 and its lower end is normally fixed to the upper end of a funnel extension tube 31. In accordance with the present invention, the shape of the fun-, nel 30 has been modified and it is supported in a different manner so that the lower portion extends into and is slidably connected to the upper portion of the extension tube 31, in a manner and for purposes to be presently described.

' A cylinder raising tube 33 (FIG. is supported beneath the needle cylinder and the sleeve gear 12, in the usual manner. A pattern drum 34 is supported on the knitting machine and is normally rotated in a step by-step manner to control the various operations of the knitting machine. This pattern drum 34 normally makes one complete rotation with the knitting of each hosiery article.

A welt presser W, shown in cross-section in FIGS. 3 and 4, is supported in the usual manner and extends inwardly beneath the level of the lower surface of the dial bed 22 and the inner end portion has a rounded portion which terminates in the line of movement of the cutting means A, for purposes to be presently described. This welt presser W extends inwardly above the needles N at the point at which they are drawn downwardly to stitch forming level by the usual stitch cam, not shown. The welt presser W normally presses inwardly against the fabric at the beginning of the formation of the turned welt of a hosiery blank.

In accordance with the present invention, the cutter means A includes a cutter support ring 35 which is fixed to the inner surface of the inner sinker ring by any suitable means, such as set screws 35b (FIG. 3). 1

As best shown in FIG. 6, the cutter support ring 35 is provided with an upstanding integral portion 350 and is vertically slotted to receive a pair of guide plates 36, 37. The upper ends of the guide plates 36, 37 are suitably connected to opposite sides of the vertical slot in the cutter support ring 35 and their lower ends are spanned by a support pin 38, opposite end portions of which are fixedly secured in the guide plates 36, 37.

A pair of fixed cutter blade plates 40, 41 are supported inside of the corresponding plates 36, 37 and the upper surface of the plate 41 is slanted downwardly or beveled to provide a cutting edge 42. The outer edges of the upper portions of the plates 40, 41 are provided with corresponding extensions 40a, 41a which serve as sinker supports, in a manner to be presently described. A vertically movable cutter blade 44 is supported between the plates 40, 41 and has a curved nose portion 45 at its upper end. A downwardly and inwardly slanting cutting blade portion 46 is positioned beneath the curved nose portion 45 and cooperates with the cutting blade portion 42 of the fixed blade 41 when the blade 44 is lowered, in a manner to be presently described.

A horizontal edge 47 is formed beneath the cutting blade portion 46 and a vertical guide rail 50 is provided on the rear edge portion of the blade 44. Notches 40b, 41b are provided on the lower portions of the respective plates 40, 41 and fit over the support pin 38 to maintain the lower portions of the plates 40, 41 in position. A lock pin 52 (FIG. 6) penetrates suitable openings in the upper portions of the plates 36, 37 and 40, 41 and one end of the pin 52 is bent and positioned in an opening 53 to maintain the pin 52in position. The pins 38 and 52 thus form a guide for the front of the cutter blade 44 and the guide rail 50 guides the inner portion of the blade 44 as it moves up and down between the plates 40, 41.

The lower portion of the blade 44 extends downwardly below the level of the adjacent plates 40, 41 and has the upper end of a tension spring 55 suitably connected thereto. The lower end of the spring 55 is connected to a suitable spring perch on the upper end of the sleeve gear 12 (FIG. 3) so that the blade 44 is normally urged to its lowermost position. An inwardly projecting butt or support 60 is provided on the rear of the movable cutter blade 44 and engages the upper surface ofthe cam means B (FIG. 1).

Resilient means is provided for maintaining the movable cutter blade 44 in close engagement with the fixed cutting blade portion 42. In the present instance, a pair of compression springs 48, 49 (FIG. 6) are supported in bores in the upstanding portion 35a of the cutter support ring 35 and their inner ends engage the outer sides of the respective plates 40, 41 (FIG. 9) to resiliently urge then against corresponding sides of the vertically movable cutter blade 44. Set screws 48a, 490 are threadably supported in the bores and engage the outer ends of the corresponding springs 48, 49 so that the amount of spring pressure against the plates 40, 41 may be adjusted, as desired.

The inside sinker ring 15 is cut away to provide a vertical groove 61 (FIG. '5) so that the plates 36, 37 and 40, 41 and vertically movable cutter blade 44 extend downwardly therein, as shown in FIGS. 3 and 4. The vertical groove 61 forms an open channel extending down inside of the needle cylinder 10 to provide sufficient clearance for the positioning of the cutting means A.

The cam means B includes a cam ring 62 having a substantially flat upper cam surface provided with any desired number of operating notches, two of which are indicated at 63 in FIG. 3. The cam ring 62 is fixed on the upper end of a cutter control tube 64 by any suitable means, such as set screws 65 (FIG. 3).

In accordance with the present invention, the funnel 30 is fixed to the upper end of the inner portion of the cutter control tube 64 by any suitable means, such as screws 66 and the lower portion of the funnel is supported for vertical sliding movement in the upper end of the funnel extension tube 31. An elongate opening 640 (FIG. 3) is provided in the tube 64 and adjacent the cutter blade tension spring 55 to provide access thereto so that it may be disconnected, when it becomes necessary to remove the cutter blade 44.

When the control means C, to be presently described, is operated to lower the control tube 64 and the cam ring 62, the spring 55 will maintain its downward pull on the blade 44 to maintain the butt 60 in engagement with the upper surface of the cam ring and lower the upper curved nose portion 45 of the blade 44 below the level of the fabric F as it is drawn from the needles N and downwardly through the funnel 30 and needle cylinder 10, as illustrated in FIG. 4. When the control tube 64 is raised, the cam ring 62 will raise the cutter blade 44 so that its upper curved nose portion 45 is above the level of the path of travel of the fabric, to the level shown in FIG. 3.

As shown in FIG. 3, the upper curved nose portion 45 of the cutter 44 extends to a level above the lower surface of the dial bed 22 and into an opening 69 formed therein. The opening 69 is provided in the dial bed between adjacent grooves which support the transfer bits 24. Since the dial rotates in unison with the needle cylinder 10, the opening 69 is maintained in alignment with the vertically movable cutter blade 44. Thus, vertical movement of the cutter blade 44 will not interfere with the normal operation of the dial and the transfer bits carried thereby. Also, since the cutter blade is positioned inwardly from the needles N, as illustrated in FIG. 3,,the operation of the cutter blade 44 will not interfere with the normal operation of the needles N.

The control means C includes an operating shaft 70 (FIG.

5) which is fixed at its inner end to the lower portion of the control tube 64 and extends outwardly through a notch in a guide plate 71 which is fixed on the cylinder raising tube 33. The notch in the guide plate 71 permits raising of the shaft 70 and prevents rotation of the tube 64. The outer portion of the operating shaft 70 is provided with a cam roller 70a which rides on the upper cam surface of the vertical arm of a psitioning bell crank 72, pivotally supported on a stub shaft 73. The stub shaft 73 is supported in a bracket 74 which is connected at its lower end to the cylinder raising tube 33.

The outer end of the horizontal arm of the bell crank 72 is connected to the upper end of an adjustable control link 76, the lower end of which is suitably connected to one end of a pattern lever 77. The medial portion of the pattern lever 77 is adapted to ride on the peripheral surface of the pattern drum 34 and is at times, engaged by a cam 78. A tension spring 80 is connected at its lower end to the outer end of the horizontal arm of the bell crank 72 and at its upper end is connected to a spring perch post 81, extending outwardly from the guide plate 71. A tension spring 82 is connected at its lower end to the stub shaft 73 and its upper end is connected to the outer end of the operating shaft 70.

When the cam 78 is out of engagement with the pattern lever 77, as shown in FIG. 5, the cam surface on the vertical arm of the bell crank 72 supports the control shaft 70 at the lower level shown and the cam ring 62 occupies the lower level shown in FIG. 4. The spring 55 maintains the butt 60 of the cutter blade 44 downwardly in contact with the cam ring 62 so that the upper curved nose portion 45 is moved downwardly between the plates 40, 41 and is maintained beneath the level of the fabric F as it is drawn downwardly into the funnel 30 and inside the needle cylinder 10.

On the other hand, when the cam 78 engages the pattern lever 77, the bell crank 72 will be moved in a counterclockwise direction in FIG. sothat the upper cam surface raises the control shaft 70 to thereby raise the control tube 64 and cam ring 62. As the cam ring 62 is raised to the upper level shown in FIG. 3, the movable cutter blade 44 is raised to the operative position so that the fabric is guided into and cut by the vertically movable blade 44 each time that the butt 60 engages a notch 63 in the cam ring 62 to thereby lower the cutting blade 44. As shown in FIG. 3, the cutter blade 44 will be lowered to a cutting position, relative to the fixed cutting blade 42, two times with each rotation of the needle cylinder. The fabric is cut at a point spaced inwardly from the needles N so that several uncut courses of fabric remain between the needles and the cutter blade, as illustrated in FIG. 2. Of course, additional notches 63 may be provided in the cam ring 62 to cause the cutter blade to operate more often, if desired.

In order to more accurately guide and support the fabric F as it moves from the needles N to the cutter blade 44, one or more special-sinkers, indicated at S' in FIGS. 1 and 2, are supported adjacent the movable cutter blade 44. The cutter blade 44 is in radial alignment with a conventional sinker S, which has a relatively short upper nose, as illustrated in the left-hand portion of FIG. 3. As shown in FIG. 1, two special sinkers S' are provided on each side of the conventional sinker S and at each side of the cutter blade 44. These special sinkers S are provided with elongated nose portions which extend over the upper portion of the raised portion 35a of the cutter support ring 35 (FIG. 1) and adjacent opposite sides of the horizontal portion 47 of the cutter blade 44.

These elongated upper noses of the sinkers S support the fabric and guide it into the cutting surface 46 of the cutter blade 44. The distance between the needles N and sinkers S and S has been somewhat exaggerated in FIGS. 1 and 2 to more clearly show the positioning of the cutter blade 44. With the sinkers closely spaced, as is normal in fine gauge hosiery knitting machines, the projections 40a, 41a (FIG. 6) engage the lower surfaces of the elongated noses of the special sinkers S to support their inner ends.

As shown in FIG. 3, the welt presser W extends inwardly beneath the lower surface of the dial bed 22 and its inner end tenninates inside of the path of travel of the the cutter blade 44 and just beneath the outer portion of the angular cutting blade portion 46. Thus, the fabric is guided between the lower surface of the welt presser W and the upper surface of the elongated noses of the sinkers S from the time it leaves the needles N until it is positioned in the cutter blade 44 so that the fabric can not roll or curl.

As shown in FIG. 2, the cutter blade is positioned inside of the needle circle and is spaced inwardly a sufficient distance that one or more courses are formed before the coursewise extending portions of the yarn in successive courses is cut so that the operation of the cutter blade 44 does not interfere with the normal operation of the needles. In the knitting of hosiery blanks suitable for the formation of panty hose, this positioning of the cutterblade does not interfere with the make-up of the fabric on the bare needles at the beginning of the knitting of the stocking, nor does it interfere with the formation of a turned welt on the hosiery blank. Also, it is possible with the present slitting apparatus to inlay spandex or other types of elastic or stretch yarns in the knit fabric.

In knitting a hosiery blank suitable for use in forming a panty hose with a walewise slit extending downwardly a predetermined distance from the upper end, the pattern drum 34 (FIG. 5) will be rotated to a position where the cam 78 will be in contact with the pattern lever 77 so that the cam ring 62 will be raised and the cutter blade 44 will be raised to the active or operative position shown in FIGS. 1 and 3. As the needle cylinder 10 rotates and yarn is fed to the needles N to form the make-up, in the usual manner, the vertically movable cutter 44 will be lowered to a cutting position each time that the butt 60 engages a notch 63 in the cam ring 62 but this cutting action will not affect the usual laying in of the yarn on the needles during the formation of the make-up because the cutter blade 44 is spaced a sufficient distance inside of the needles that it will not engage any yarn extending between the needles.

Air currents are drawn inwardly beneath the dial 22 and down through the funnel extension tube 31 by the usual pneumatic take-down, not shown, to draw the fabric into the cutter 44, as shown in FIG. 2. The fabric is cut or slit in a walewise direction each time the cutter blade 44 is lowered, by engagement of the butt 60 with a notch 63 in the cam ring 62.

When the slit has been formed of the desired length, the cam 78 on the pattern drum 34 will move out of engagement with the pattern lever 77 so that the control tube 64 and the cam ring 62 are lowered to the position shown in FIG. 4. The cutter blade 44 is then positioned below the level of the fabric F and will not interfere with the normal knitting operation so that the uncut fabric is drawn downwardly through the funnel 30 and the extension tube 31. As shown in FIG. 4, the upper surface of the cam ring and the blade 44 is supported on the pin 52 so that the butt 60 does not engage the operating notches 63 and the blade 44 does not operate when in this lowermost or inactive position.

In addition to the upper or active position of the control blade, shown in FIG. 3, and the lower or fully inactive position shown in FIG. 4, the cutter blade 44 may also occupy an intermediate position between these two extremes. In this intermediate position, the upper curved portion 45 is just below the level of the fabric so that the cutter blade 44 does not cut the fabric. When in this intermediate position, the vertically movable blade 44 will be raised and lowered as the operating butt 60 engages the notches 63 so that any uncut yarns which may be trapped between the blade 44 and the plates 40, 41 will be cut and released. The movement of the cutter blade 44 to this intermediate position at the end of the slitting operation prevents any picks which might be caused by yarns trapped in the cutter.

The vertically movable blade 44 is moved to the intermediate position as the pattern lever 77 engages a reduced tail portion 79 on the cam 78 (FIG. 5). This reduced tail portion be lowered sufficiently that the upper end of the movable 79 moves the bell crank 72 to a position where the upper cam surface thereof permits the control tube 64 and cam ring 62 to cutter blade 44 is positioned just below the path of movement of the fabric. In this intermediate position, the butt 60 does engage the upper surface of the cam ring 62 and the operating notches 63 so that the blade 44 continues to operate to cut any yarn ends held therein but is not raised high enough to cut the fabric.

Thus, the slitting apparatus of the present invention includes a vertically movable cutter blade which is positioned inside of the needle cylinder and closely adjacent the circle of needles but doe not interfere with the normal operations of the knitting machine. Cam means is also provided for imparting vertical movement to the cutter blade in timed relationship to the knitting of the fabric to thereby slit the fabric as it is being formed. Control means is provided for selectively moving the cutter blade between operative and inoperative positions so that the tubular fabric may be selectively slit when desired.

While the present slitting apparatus has been described in connection with the formation of a walewise slit extending inwardly for a predetermined length from the leading end of a tubular fabric, it is to be understood that the present slitting apparatus may. also be utilized in fonning a slit in a medial portion of the tubular fabric or forming a slit extending from a medial portion to a trailing end of the tubular fabric. When knitting course gauge, open mesh knit fabrics, the upper curved end 45 of the movable cutter blade 44 may be raised to pass directly through the fabric so that the slit may be started without any modification of the described operation.

When knitting a fine gauge, dense fabric, the upper end of the movable cutter blade 44 will not easily pass through the fabric. To provide a starting point for the slit, several adjacent needles could pass the knitting station without knitting to form short floats in successive courses and at the point where the slit is to begin. The upper end of the blade 44 could then be moved upwardly through this area of the fabric, in the wales where the floats are formed.

In the drawings and specification there has been set forth a preferred embodiment of the invention and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.

I claim:

1. In a circular knitting machine including a needle cylinder with needles supported for vertical movement therein and forming a circle of needles for knitting a tubular fabric, the tubular fabric being drawn inwardly and downwardly through said needle cylinder, the combination therewith of means for slitting the tubular fabric in a walewise direction immediately after the fabric is knit, said slitting means comprising a. cutter means including a vertically movable cutter blade positioned inside of and extending above the upper level of said needle cylinder and closely adjacent said circle of needles, and

b. cam means operably associated with said cutter blade to impart vertical movement thereto in timed relationship to the knitting of the fabric and to sever coursewise extending portions ofthe yarn in successive courses so that the fabric is slit in a walewise direction.

2. In a circular knitting machine according to claim 1 including control means operably associated with said cam means for, at times, positioning said cutter blade in the path of movement of the fabric as it is drawn from the needles to slit the fabric in a walewise direction, and for, at other times, maintaining said cutter blade below the level of the fabric so that the fabric is not slit thereby.

3. In a circular knitting machine according to' claim 1 wherein said cutter means (a) includes at least one fixed cutter blade positioned adjacent said movable cutter blade, and resilient means for maintaining said fixed cutter blade in engagement with said vertically movable cutter blade.

4. In a circular knitting machine according to claim 1 wherein said needle cylinder rotates during knitting of the tubular fabric, wherein said movable cutter blade includes an inwardly projecting operating butt, and wherein said cam means (b) includes a cam ring supported in a nonrotating position inside of said needle cylinder, at least one cam notch formed in the upper surface of said cam ring, resilient means normally urging said operating butt of said vertically movable cutter blade downwardly into engagement with the upper surface of said cam ring and into engagement with said cam notch so that said movable cutter blade is lowered to a cutting position upon engagement of said butt with said cam notch in said cam ring.

5. In a circular knitting machine according to claim 1 wherein said machine includes sinkers supported for radial sliding movement between certain of said needles and having inner nose portions terminating outside of the position of said movable cutter blade, and wherein said cutter means includes at least one special sinker positioned adjacent said movable cutter blade and including an elongated nose portion extending inwardly beyond the outer extremity of said cutter blade to support and guide the fabric into said movable cutter blade.

6. In a circular knitting machine according to claim 4 wherein said cutter means (a) includes a cutter support ring positioned inside of said needle cylinder and rotating therewith, and means on said cutter support ring for guidingly supporting said vertically movable cutter blade therein.

7. In a circular knitting machine according to claim 4 including a dial rotating in timed relationship to rotation of said needle cylinder, said dial having an outer peripheral portion extending outwardly above said vertically movable cutter blade, transfer bits supported in said dial for radial movement, said dial having an opening formed therein and above said vertically movable cutter blade so that the upper end portion of said vertically movable cutter blade may be raised into the opening in said dial.

8. In a circular knitting machine according to claim 4 wherein said slitting means includes control means operably associated with said cam ring for, at times, positioning said cutter blade in the path of movement of the fabric as it is drawn from the needles to slit the fabric in a walewise direction and for, at other times, maintaining said cutter blade below the level of the fabric so that the fabric is not slit thereby, said control means including a control tube extending upwardly inside of said needle cylinder, means supporting said cam ring on the upper end of said control tube, and pattern control means for, at times, raising said control tube to raise said vertically movable cutter blade to an active position and for, at other times, lowering said control tube to lower said vertically movable cutter blade to an inactive position.

9. In a circular knitting machine according to claim 8 wherein said pattern control means includes a pattern drum rotatable in timed relationship to operation of said knitting machine, cam means supported on said pattern drum, and control linkage operable by said cam means and operatively connected to said control tube for selectively raising and lowering said control tube.

10. A method of slitting tubular fabric in a walewise direction immediately after the fabric is knit on a circular knitting machine including a rotating needle cylinder with needles supported for vertical movement therein and forming a circle of needles for knitting a tubular fabric, the tubular fabric being drawn inwardly and downwardly through said needle cylinder, said method comprising the steps of a. at times, positioning a vertically movable cutter blade in the path of travel of the fabric above the upper level of the needle cylinder, and immediately adjacent said circle of needles and severing coursewise extending portions of the yarn in successive courses to slit the fabric in a walewise direction, and

b. at other times, positioning said cutter beneath the path of travel of the fabric so that said cutter does not engage the fabric and the tubular fabric is not slit thereby.

UNITED STATES PATENT OFFICE CERTIFICATE OF' CORRECTION Patent No. 28 I Dated June 20, 1972 Inventor(s) Oscar g lle It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected. as shown below:

Column 7, Li e-6, change "doe" to does Column 8, Line 60, (Claim 10) cancel "vertically movable" and "blade Signed and sealed this 7th day of November 1972.

(SEAL) Attest:

EDWARD M-FLETCHERJRQ ROBERT GOTTSCHALK Attesting Officer- Commissioner of Patents FORM PO-105OHO-69) USCOMM-DC 60376-1 69 a u.s. GOVERNMENT PRINTING OFFICE: I969 o-35s334 

1. In a circular knitting machine including a needle cylinder with needles supported for vertical movement therein and forming a circle of needles for knitting a tubular fabric, the tubular fabric being drawn inwardly and downwardly through said needle cylinder, the combination therewith of means for slitting the tubular fabric in a walewise direction immediately after the fabric is knit, said slitting means comprising a. cutter means including a vertically movable cutter blade positioned inside of and extending above the upper level of said needle cylinder and closely adjacent said circle of needles, and b. cam means operably associated with said cutter blade to impart vertical movement thereto in timed relationship to the knitting of the fabric and to sever coursewise extending portions of the yarn in successive courses so that the fabric is slit in a walewise direction.
 2. In a circular knitting machine according to claim 1 including control means operably associated with said cam means for, at times, positioning said cutter blade in the path of movement of the fabric as it is drawn from the needles to slit the fabric in a walewise direction, and for, at other times, maintaining said cutter blade below the level of the fabric so that the fabric is not slit thereby.
 3. In a circular knitting machine according to claim 1 wherein said cutter means (a) includes at least one fixed cutter blade positioned adjacent said movable cutter blade, and resilient means for maintaining said fixed cutter blade in engagement with said vertically movable cutter blade.
 4. In a circular knitting machine according to claim 1 wherein said needle cylinder rotates during knitting of the tubular fabric, wherein said movable cutter blade includes an inwardly projecting operating butt, and wherein said cam means (b) includes a cam ring supported in a nonrotating position inside of said needle cylinder, at least one cam notch formed in the upper surface of said cam ring, resilient means normally urging said operating butt of said vertically movable cutter blade downwardly into engagement with the upper surface of said cam ring and into engagement with said cam notch so that said movable cutter blade is lowered to a cutting position upon engagement of said butt with said cam notch in said cam ring.
 5. In a circular knitting machine according to claim 1 wherein said machine includes sinkers supported for radial sliding movement between certain of said needles and having inner nose portions terminating outside of the position of said movable cutter blade, and wherein said cutter means includes at least one special sinker positioned adjacent said movable cutter blade and including an elongated nose portion extending inwardly beyond the outer extremity of said cutter blade to support and guide the fabric into said movable cutter blade.
 6. In a circular knitting machine according to claim 4 wherein said cutter means (a) includes a cutter support ring positioned inside of said needle cylinder and rotating therewith, and means on said cutter support ring for guidingly supporting said vertically movable cutter blade therein.
 7. In a circular knitting machine according to claim 4 including a dial rotating in timed relationship to rotation of said needle cylinder, said dial having an outer peripheral portion extending outwardly above said vertically movable cutter blade, transfer bits supported in said dial for radial movement, said dial having an opening formed therein and above said vertically movable cutter blade so that the upper end portion of said vertically movable cutter blade may be raised into the opening in said dial.
 8. In a circular knitting machine according to claim 4 wherein said slitting means includes control means operably associated with said cam ring for, at times, positioning said cutter blade in the path of movement of the fabric as it is drawn from the needles to slit the fabric in a walewise direction and for, at other times, maintaining said cutter blade below the level of the fabric so that the fabric is not slit thereby, said control means including a control tube extending upwardly inside of said needle cylinder, means supporting said cam ring on the upper end of said control tube, and pattern control means for, at times, raising said control tube to raise said vertically movable cutter blade to an active position and for, at other times, lowering said control tube to lower said vertically movable cutter blade to an inactive position.
 9. In a circular knitting machine according to claim 8 wherein said pattern control means includes a pattern drum rotatable in timed relationship to operation of said knitting machine, cam means supported on said pattern drum, and control linkage operable by said cam means and operatively connected to said control tube for selectively raising and lowering said control tube.
 10. A method of slitting tubular fabric in a walewise direction immediately after the fabric is knit on a circular knitting machine including a rotating needle cylinder with needles supported for vertical movement therein and forming a circle of needles for knitting a tubular fabric, the tubular fabric being drawn inwardly and downwardly through said needle cylinder, said method comprising the steps of a. at times, positioning a vertically movable cutter blade in the path of travel of the fabric above the upper level of the needle cylinder, and immediately adjacent said circle of needles and severing coursewise extending portions of the yarn in successive courses to slit the fabric in a walewise direction, and b. at other times, positioning said cutter beneath the path of travel of the fabric so that said cutter does not engage the fabric and the tubular fabric is not slit thereby. 